CUET Preparation Today
If A is a matrix of order 3 and |adj A| = 7 , then the value of |A| is |
\(\sqrt { 7 }\) - \(\sqrt { 7 }\) Both (a) and (b) None |
Both (a) and (b) |
We know that |adj A| = \( { |A| }^{ n-1 } \) , where n is the order of matrix A. So, |adj A| = \( { |A| }^{ 3-1 } \) = \( { |A| }^{ 2 } \) 7 = \( { |A| }^{ 2 } \) |A| = \(\sqrt { 7 }\), -\(\sqrt { 7 }\) |
